The present invention relates to a semiconductor device which is referred to as a CSP (Chip Size Package), a BGA (Ball Grid Array) or the like and a method for manufacturing this semiconductor device.
A semiconductor device which is referred to as, for instance, a BGA is shown in reference to FIG. 9 and has, a semiconductor chip 101 mounted at a front surface of an internal substrate 100 (the upper surface in FIG. 9), and the semiconductor chip 101 and the internal substrate 100 are electrically connected through wiring 102 in the prior art. Then, the semiconductor chip 101 is sealed with a resin 103 on the front surface of the internal substrate 100. In addition, the semiconductor device assumes a structure achieved by providing solder bumps (solder balls) 104 at a rear surface of the internal substrate 100 (the lower surface in FIG. 9).
In recent years, the need for achieving higher density mounting with this type of semiconductor device has become more pronounced. However, the semiconductor device in the prior art explained with reference to FIG. 9, which device fails to effectively utilize the area of the substrate over which mounting is possible when mounting at a motherboard, it is difficult to reduce the mounting area to a sufficient degree. Consequently, it is difficult to respond to the high density mounting requirement in a satisfactory manner.
Furthermore, since the reliability of the semiconductor device in the prior art, which is tested in a temperature cycling test conducted after soldering it at a motherboard is problematic, the reliability in the temperature cycling test is improved by filling the space between the semiconductor device and the motherboard with resin to hold down the electrically connected portions with the resin. However, there is a problem in that, in order to fill the space between the semiconductor device and the motherboard with resin, the number of steps to be implemented in the resin sealing process must be increased.